WO2021128513A1

WO2021128513A1 - Organic light-emitting display panel, preparation method therefor and organic light-emitting display

Info

Publication number: WO2021128513A1
Application number: PCT/CN2020/071908
Authority: WO
Inventors: 邴一飞
Original assignee: 深圳市华星光电半导体显示技术有限公司
Priority date: 2019-12-23
Filing date: 2020-01-14
Publication date: 2021-07-01
Also published as: US20210408176A1; CN111063817A

Abstract

Disclosed are an organic light-emitting display panel, a preparation method therefor, and an organic light-emitting display. The organic light-emitting display panel comprises: a substrate; positive electrodes and a pixel definition layer, wherein the pixel definition layer is enclosed to form a plurality of grooves arranged in an array, the positive electrodes are located in the grooves on a one-to-one basis, and the pixel definition layer comprises a first retaining wall, a second retaining wall and a third retaining wall; a first organic light-emitting layer, a second organic light-emitting layer and a third organic light-emitting layer which are located on the positive electrodes, wherein at least one spacing region is formed between every two layers; and an electron transport layer and negative electrodes.

Description

Organic light-emitting display panel and preparation method thereof, and organic light-emitting display

Technical field

The present invention relates to the field of display technology, in particular to an organic light-emitting display panel, a preparation method thereof, and an organic light-emitting display.

Background technique

Organic Light-Emitting Diode (OLED, also known as Organic Light-Emitting Diode) display panel has the advantages of low cost, wide viewing angle, high contrast, and bendable. At present, the application of small size and large size has achieved remarkable results. The results are constantly invading the market share of LCD monitors.

The OLED display panel includes a substrate, and an anode electrode, an organic light-emitting layer, and a cathode electrode sequentially formed on the substrate. At present, the most common preparation method for forming an organic light-emitting layer is vacuum thermal evaporation (VTE), that is, heating organic small molecule materials in a vacuum chamber to sublime or melt and vaporize them into steam, and then deposit them on the metal mask through the openings. On the substrate. However, the vacuum thermal evaporation method is limited by the size of the vacuum cavity and the size of the mask, so the preparation of a larger area organic OLED display panel is restricted.

Compared with vacuum thermal evaporation, the inkjet printing process has some important advantages. Its main working principle is to eject ink from tiny nozzles under the control of a computer program and land on the designated position of the substrate, and finally form a pre-designed pattern. The material utilization rate of the process can reach 100%, and the process cycle time can be reduced by increasing the number of nozzles, and it is suitable for preparing large-size OLED display panels. At the same time, the inkjet printing process does not need to build a vacuum chamber, and the manufacturing cost is lower.

Generally, when using an inkjet printing process to make an OLED panel, it is necessary to first form a corresponding pixel definition layer on the substrate to define the ink film forming area. After inkjet printing, the pixel definition layer will be filled with the specified ink. However, when the ink is dripped, due to the large amount of ink in the pixel definition layer, ink mixing often occurs at the boundary of the pixel definition layer This phenomenon leads to the shift and color mixing of the final pixel's light-emitting color, which reduces the product yield.

technical problem

In the prior art, when an organic light-emitting layer is formed by an inkjet printing process, the problem of poor light emission caused by the mixing of different color inks in adjacent pixel regions.

Technical solutions

The present invention provides an organic light emitting display panel, including:

Substrate

The anode electrode and the pixel defining layer are located on the substrate, the pixel defining layer surrounds and forms a plurality of grooves arranged in an array, the anode electrodes are located in the grooves one by one, and the plurality of grooves includes A number of first grooves, a number of second grooves, and a number of third grooves. The pixel definition layer includes a first retaining wall, a second retaining wall, and a third retaining wall. The first groove is located in the first retaining wall. Between the retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located between the third retaining wall and the third retaining wall. Between the first retaining wall;

The organic light-emitting layer is located on the anode electrode and includes a first organic light-emitting layer, a second organic light-emitting layer, and a third organic light-emitting layer. The first organic light-emitting layer is located in the first groove, and the second organic light-emitting layer is The layer is located in the second groove, and the third organic light-emitting layer is located in the third groove, wherein at least between the first organic light-emitting layer, the second organic light-emitting layer and the third organic light-emitting layer is at least Form a compartment;

An electron transport layer covering the first organic light-emitting layer, the second organic light-emitting layer, the third organic light-emitting layer, the pixel defining layer, and the spacer;

The cathode electrode covers the electron transport layer.

To achieve the above objective, the present invention further provides an organic light emitting display, the organic light emitting display includes an integrated circuit and the organic light emitting display panel as described above, and the integrated circuit is connected to the organic light emitting display panel.

To achieve the above objective, the present invention additionally provides a method for manufacturing an organic light emitting display panel, including:

Provide a substrate;

An anode electrode and a pixel definition layer are formed on the substrate, the pixel definition layer surrounds and forms a plurality of grooves arranged in an array, the anode electrodes are located in the grooves one by one, and the plurality of grooves includes A number of first grooves, a number of second grooves, and a number of third grooves. The pixel definition layer includes a first retaining wall, a second retaining wall, and a third retaining wall. The first groove is located in the first retaining wall. Between the retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located between the third retaining wall and the third retaining wall. Between the first retaining wall;

By inkjet printing, drop the ink with the first organic light-emitting material into the first groove and form a film to form the first organic light-emitting layer, and drop the ink with the second organic light-emitting material into the second recess. The second organic light-emitting layer is formed by forming a film in the groove, and the ink with the third organic light-emitting material is dropped into the third groove and formed into a film to form a third organic light-emitting layer, wherein the first organic light-emitting layer At least a spacer is formed between the layer, the second organic light-emitting layer and the third organic light-emitting layer;

Forming an electron transport layer covering the first organic light emitting layer, the second organic light emitting layer, the third organic light emitting layer, the pixel defining layer, and the spacer;

A cathode electrode covering the electron transport layer is formed.

Beneficial effect

In the present invention, the pixel defining layer is arranged as the first retaining wall, the second retaining wall, and the third retaining wall. The pixel defining layer surrounds the first groove, the second groove, and the third groove arranged in an array. , The first groove is located between the first retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located between the third retaining wall and the first retaining wall In between, the first, second, and third grooves are dripped with ink dissolved in organic light-emitting materials to form an organic light-emitting layer, the first organic light-emitting layer, the second organic light-emitting layer, and the third organic light-emitting layer At least one spacer is formed between the spacers. By blocking the spacers, the mixing of inks with different organic light-emitting materials dissolved between adjacent grooves is avoided, which is beneficial to avoid pixel emission color shift and color mixing in the OLD display panel. unpleasant sight.

Description of the drawings

FIG. 1 is a schematic diagram of dripping ink using an inkjet printing process in the prior art;

2 is a schematic cross-sectional view of an organic light-emitting display panel prepared by an inkjet printing process in the prior art;

3 is a schematic diagram of dripping ink using an inkjet printing process according to an embodiment of the organic light emitting display panel of the present invention;

4 is a schematic cross-sectional view of an embodiment of the organic light emitting display panel of the present invention;

5 is a schematic diagram of dripping ink using an inkjet printing process in another embodiment of the organic light emitting display panel of the present invention;

6 is a schematic cross-sectional view of another embodiment of the organic light emitting display panel of the present invention;

FIG. 7 is a schematic flow chart of the manufacturing method of the organic light emitting display panel of the present invention.

Embodiments of the present invention

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not used to limit the present invention. In the case of no conflict, the following embodiments and their technical features can be combined with each other.

The description of the following embodiments refers to the attached drawings to illustrate specific embodiments in which the present invention can be implemented. The directional terms mentioned in the present invention, such as [up], [down], [front], [back], [left], [right], [inside], [outside], [side], etc., are for reference only The direction of the additional schema. Therefore, the directional terms used are used to describe and understand the present invention, rather than to limit the present invention. In the figure, units with similar structures are indicated by the same reference numerals.

Please refer to FIG. 1 and FIG. 2, which are a schematic diagram of the ink dripping of an organic light-emitting display panel prepared by an inkjet printing process in the prior art and a schematic cross-sectional view of the organic light-emitting display panel.

First, it is necessary to fabricate an anode 12 and a pixel definition layer on the substrate 11. Layer, PDL) 13. The pixel defining layer 13 is used to define the red pixel area 14a, the green pixel area 14b, and the blue pixel area 14c arranged in an array, and then use an inkjet printing process in the red pixel area 14a, the green pixel area 14b, and the blue pixel area. The regions 14c are respectively filled with inks 141, 142, and 143 in which organic light-emitting materials are dissolved, and finally are respectively formed as organic light-emitting layers for emitting red light, green light, and blue light. Among them, the inks 141, 142, and 143 have relatively low concentrations. In order to achieve the predetermined thickness of the organic light-emitting layer, the pixel definition layer 13 needs to be able to hold a sufficient amount of ink. The thickness of the organic light-emitting layer of each color is different. Specifically, the ink 141 dissolving the red organic light-emitting material 141R is more than the ink 142 dissolving the blue organic light-emitting material 142B and the ink 143 dissolving the green organic light-emitting material 143G, which will result in the definition of the pixel at the boundary of the pixel area. The ink mixing phenomenon occurs on the layer 13, that is, the ink 141 with the red organic light-emitting material 141R and the ink 142 with the blue organic light-emitting material 142B and the ink 143 with the green organic light-emitting material 143G in the boundary of the pixel definition layer 13 On the mix.

This ink mixing phenomenon will cause a certain pixel area of the finally formed OLED display panel 10 to contain two or more organic light-emitting materials at the same time. As shown in FIGS. 1 and 2, the blue pixel area 14c also contains The blue organic light-emitting material 142B and the red organic light-emitting material 141R. The red pixel region 14a not only contains the red organic light-emitting material 141R, but also the two ends of the red organic light-emitting material 141R are respectively doped with blue organic light-emitting material 142B and green organic light-emitting material. The material 143G, and the green pixel region 14b contains both the green organic light-emitting material 143G and the red organic light-emitting material 141R, so that the OLED display panel 10 has problems of poor light emission such as pixel light emission color shift and color mixing.

Therefore, it is necessary to provide an organic light emitting display panel to solve the problem of poor light emission caused by the mixing of different color inks in adjacent pixel regions when the organic light emitting layer is formed by the inkjet printing process.

Please refer to FIGS. 3 to 4, an organic light emitting display panel 30 provided by an embodiment of the present invention includes a substrate 31, an anode electrode 32, a pixel definition layer 33, an organic light emitting layer 34, an electron transport layer 35 and a cathode electrode 36. among them:

The substrate 31 is used to carry various structural layers and electronic components of the OLED display panel 30. It can be a glass substrate, a plastic substrate, or a rigid substrate, which is not limited here. When preparing an OLED display, the substrate 11 may be a flexible substrate, such as a polyimide (PI) substrate.

A buffer layer may be provided on the substrate 31. The buffer layer has the function of blocking water and oxygen, and its main components include but are not limited to silicon nitrogen compound (SiN _x ), silicon oxygen compound (SiO _x ), silicon oxynitride (SiO _x N _y). )Wait. When a buffer layer is provided, the structural layers and electronic components of the OLED display panel 30, such as the anode electrode 32 and the pixel definition layer 33, are located on the buffer layer.

The anode electrode 32 and the pixel definition layer 33 are located on the substrate 31. The pixel defining layer 33 surrounds and forms a plurality of grooves arranged in an array, the anode electrodes 32 are located in the grooves one by one, and the organic light emitting layer 34 is also located in the grooves and covers the anode electrodes 32.

The plurality of grooves includes a plurality of first grooves 33a, a plurality of second grooves 33b, and a plurality of third grooves 33c. The first groove 33a, the second groove 33b, and the third groove 33c are each provided with an anode electrode 32 and an organic light emitting layer 34.

Further, the pixel definition layer 33 includes a first retaining wall 331, a second retaining wall 332, and a third retaining wall 333. Among them, the first groove 33a is located between the first retaining wall 331 and the second retaining wall 332, the second groove 33b is located between the second retaining wall 332 and the third retaining wall 333, and the third groove 33c is located on the third retaining wall. Between the retaining wall 333 and the first retaining wall 331.

The organic light emitting layer 34 includes a first organic light emitting layer 341, a second organic light emitting layer 342, and a third organic light emitting layer 343. In an embodiment of the present invention, the thickness of the second organic light-emitting layer 342 and the third organic light-emitting layer 343 are equal and smaller than the thickness of the first organic light-emitting layer 341. The first organic light emitting layer 341 is located in the first recess 33a, the second organic light emitting layer 342 is located in the second recess 33b, and the third organic light emitting layer 343 is located in the third recess 33c. The first organic light-emitting layer 341 is doped with a red organic light-emitting material, the second organic light-emitting layer 342 is doped with a green organic light-emitting material, and the third organic light-emitting layer 343 is doped with a blue organic light-emitting material. The ink 344 of the red organic light-emitting material forms the first organic light-emitting layer 341, the ink 345 mixed with the green organic light-emitting material forms the second organic light-emitting layer 342, and the ink 346 mixed with the blue organic light-emitting material forms the third organic light-emitting layer. Luminescent layer 343.

In this embodiment, an inkjet printing method is used as an example to prepare an organic light-emitting layer. It is understandable that when the ink forming the organic light-emitting layer is dropped, the amount of the ink 344 mixed with the red organic light-emitting material is greater than the amount of the ink 345 mixed with the green organic light-emitting material and the blue organic light-emitting material is mixed. The amount of ink 346, so it may appear that the ink 344 mixed with red organic light-emitting material dropped in the first groove 33a and the ink 344 mixed with the second groove 33b and the third groove 33c at both ends may be mixed with green organic The ink 345 of the light-emitting material and the ink 346 mixed with the blue-emitting organic light-emitting material are mixed. Therefore, at least one spacer can be formed between the first organic light-emitting layer 341, the second organic light-emitting layer 342, and the third organic light-emitting layer 343, and the blocking effect of the provided spacer layer can prevent dripping. When the ink 344 mixed with red organic light-emitting material is large, it may be mixed with the ink 345 mixed with the green organic light-emitting material and the ink 346 mixed with the blue organic light-emitting material at both ends.

Specifically, in this embodiment, a first spacer 33d is formed between the first organic light-emitting layer 341 and the second organic light-emitting layer 342, and a first spacer 33d is formed between the first organic light-emitting layer 341 and the third organic light-emitting layer 343. The second compartment 33e. That is, the above-mentioned first spacer 33d is arranged between two adjacent first retaining walls 331, and the above-mentioned second spacer 33e is arranged between two adjacent second retaining walls 332. Through the blocking of the spacer layer, it is avoided that when there is more ink 344 mixed with red organic light-emitting material, the ink 345 mixed with green organic light-emitting material and the ink mixed with blue organic light-emitting material at both ends are avoided. 346 phase mixing phenomenon.

At the same time, because the thickness of the second organic light-emitting layer 342 and the third organic light-emitting layer 343 are equal, that is, when the ink 345 doped with the green organic light-emitting material and the ink 346 doped with the blue organic light-emitting material are dropped, both The amount of ink is equal, so there is no need to provide spacers between the second groove 33b and the third groove 33c, and only the spacers are provided at both ends of the first groove 33a.

In this embodiment, because there are spacers between the organic light-emitting layers, the height h of the first retaining wall 331, the second retaining wall 332, and the third retaining wall 333 can be set to be equal, so that adjacent pixels can be avoided. Defines the mixing phenomenon of the dripped ink in the layer.

In other embodiments, the heights of the first retaining wall 331, the second retaining wall 332, and the third retaining wall 333 may be set to be different, or for example, the heights of the first retaining wall 331 and the second retaining wall 332 are the same, but not equal to The height of the third retaining wall 333 is not equal. When the heights of the first retaining wall 331 and the second retaining wall 332 are equal but not equal to the height of the third retaining wall 333, in order to more effectively avoid ink mixing, the height of the third retaining wall 333 can be set to be greater than the height of the third retaining wall 333. The height of a retaining wall 331 and the second retaining wall 332, so that the second groove 33b located at both ends of the third retaining wall 333 is mixed with the ink 345 emitting green organic light-emitting material and the third groove 33c is mixed The ink 346 with blue organic light-emitting material is mixed.

Further, in order to facilitate the dripping of ink to form the organic light-emitting layer 34, the opposite sides of the first barrier wall 331, the second barrier wall 332, and the third barrier wall 333 are inclined relative to the substrate 31, so that the ink is not easy to overflow when dripping. .

In addition, the inclination angles θ of the first retaining wall 331, the second retaining wall 332, and the third retaining wall 333 are all equal. Therefore, it is convenient to use the same photomask etching process when forming the pixel definition layer, which saves production cost and shortens the process time.

Further, the formation of spacers between the adjacent first retaining walls 331 and the adjacent second retaining walls 332 can avoid ink mixing. Therefore, in this embodiment, the first groove 33a and the second concave The width of the groove 33b and the third groove 33c are both larger than the width of the first spacer 33d and the second spacer 33e. In other embodiments, the widths of the first groove 33a, the second groove 33b, and the third groove 33c can be set to be equal to the widths of the first spacer 33d and the second spacer 33e, so as to avoid the difference more effectively. The mixing of the ink in the groove.

In a specific embodiment, the surface of the substrate 31 may be hydrophilic, and the surfaces of the first retaining wall 331, the second retaining wall 332, and the third retaining wall 333 are all hydrophobic. Therefore, the inks 344, 345, and 346 are not easy to overflow the corresponding retaining wall, but are more likely to overflow to the substrate 31. Therefore, it is also possible to prevent the ink containing different organic luminescent materials from passing through the first retaining wall 331 and the second retaining wall 332. Mixing is beneficial to avoid poor pixel light emission in the OLED display panel 30.

In addition, after the spacers are formed, in order to prevent light leakage in the spacers, and to increase the conductivity of the panel cathodes, reduce the resistance of the panel cathodes, and improve the uniformity of panel light emission, a cathode layer 37 is first provided in the spacers to make the cathodes The layer 37 is located on the surface of the electron transport layer 35 away from the cathode electrode 36. The main material of the cathode layer 37 is a metal material, such as Ag, Al, Li, Mg, Ca and other metal materials.

The electron transport layer 35 in this embodiment covers the first organic light emitting layer 341, the second organic light emitting layer 342, the third organic light emitting layer 343, the pixel defining layer 13, and the first spacer 33d and the second spacer 33e Above the cathode layer 37.

Furthermore, the cathode electrode 36 covers the electron transport layer 35. Thus, the final OLED display panel 30 can be obtained. The material of the cathode electrode 36 in this embodiment is a metal material, which may be the same as or different from the material of the cathode layer 37. By providing a cathode layer 37 in the spacers 33d and 33e first, and then an electron transport layer 35 and a cathode electrode 36 on the entire surface, the resistance of the cathode of the entire panel is reduced, the uniformity of the panel luminescence is improved, and the luminescence of the product is further improved. performance.

Understandably, the OLED display panel 30 further includes a hole injection layer (HIL), a hole transport layer (HTL), an electron injection layer (Electron Inject layer, EIL), and the hole injection layer is formed On the anode electrode 32, the hole transport layer is formed between the hole injection layer and the organic light emitting layer, and the electron injection layer is formed between the electron transport layer 35 and the cathode electrode 36.

In the above-mentioned organic light emitting display panel 30, by setting the pixel defining layer 33 as the first retaining wall 331, the second retaining wall 332, and the third retaining wall 333, the pixel defining layer 33 surrounds the first grooves arranged in an array. 33a, the second groove 33b and the third groove 33c, the first groove 33a is located between the first retaining wall 331 and the second retaining wall 332, and the second groove 33b is located between the second retaining wall 332 and the third retaining wall 332 Between the walls 333, the third groove 33c is located between the third retaining wall 333 and the first retaining wall 331, and organic light emitting is dripped into the first groove 33a, the second groove 33b, and the third groove 33c. The ink of the material forms the organic light-emitting layer 34. The organic light-emitting layer 34 includes a first organic light-emitting layer 341, a second organic light-emitting layer 342, and a third organic light-emitting layer 343. A first spacer 33d is formed between the first organic light-emitting layer 341 and the third organic light-emitting layer 343, and a second spacer 33e is formed between the first organic light-emitting layer 341 and the third organic light-emitting layer 343. The mixing of the inks of organic light-emitting materials is beneficial to avoid the occurrence of undesirable phenomena such as pixel light-emitting color shift and color mixing in the OLED display panel 30.

Please refer to FIGS. 5 and 6, which are an OLED display panel 30 provided by another embodiment of the present invention. The OLED display panel 30 in this embodiment is substantially the same as the organic light emitting display panel 30 in the first embodiment, except that :

A third spacer 33f is formed between the second organic light-emitting layer 342 and the third organic light-emitting layer 343, that is, a third spacer 33f is formed between adjacent third barrier walls 333. Therefore, a first partition 33d is provided between adjacent first retaining walls 331, a second partition 33e is provided between adjacent second retaining walls 332, and a third gap is provided between adjacent third retaining walls 333. The area 33f, that is, the two sides of each groove are provided with spacers, which more effectively avoids the phenomenon that the ink dripped in the groove and the ink dripped in the adjacent grooves are mixed.

Further, the widths of the first groove 33a, the second groove 33b, and the third groove 33c are all greater than the width of the third spacer region 33f. In this embodiment, the widths of the first spacer 33d, the second spacer 33e, and the third spacer 33f are all equal. In other embodiments, the width of the first partition 33d and the second partition 33e may be greater than the width of the third partition 33f, because a first groove is provided between the first retaining wall 331 and the second retaining wall 332 33a, the first groove 33a is used to drop a larger volume of ink 344 with red organic luminescent material dissolved in it. When the spacing area on both sides of the first groove 33a is larger, it is more effective to avoid red dissolving The organic light-emitting material ink 344 is mixed with the green organic light-emitting material ink 345 and the blue organic light-emitting material ink 346 on both sides.

In the above-mentioned organic light emitting display panel 30, the third spacer 33f is formed between the second organic light emitting layer 342 and the third organic light emitting layer 343, so that spacers are provided on both sides of each groove, which more effectively avoids Ink 344 with red organic light-emitting material, ink 345 with green organic light-emitting material, and ink 346 with blue organic light-emitting material are all mixed with the inks on both sides, which is beneficial to avoid the pixel emission color shift of the OLED display panel 30 And undesirable phenomena such as color mixing.

The present invention also provides an OLED display in other embodiments. The OLED display includes an integrated circuit (IC) and an OLED display panel connected to the integrated circuit. The OLED display panel may have the same OLED display as any one of the foregoing embodiments. The display panel 30 has the same structure. Therefore, the OLED display can be designed to form a first spacer 33d between the first organic light-emitting layer 341 and the second organic light-emitting layer 342, and a second spacer 33d is formed between the first organic light-emitting layer 341 and the third organic light-emitting layer 343. 33e, and a third spacer is formed between the second organic light-emitting layer 342 and the third organic light-emitting layer 343, so as to realize that there are formed on both sides of the first groove 33a, the second groove 33b, and the third groove 33c. The spacer area effectively avoids the mixing of the ink dripped in the groove with the ink in the adjacent groove, and helps prevent the OLED display panel 30 from pixel emission color shift and color mixing.

Please refer to FIG. 7, which is a schematic flowchart of a manufacturing method of an OLED display panel provided by an embodiment of the present invention. The manufacturing method of the OLED display panel includes steps S71-S76.

In step S71, a substrate is provided.

The substrate is used to carry the structural layers and electronic components of the OLED display panel. It can be a glass substrate, a plastic substrate, or a rigid substrate, which is not limited here. When preparing an OLED display, the substrate may be a flexible substrate, such as a polyimide (PI) substrate.

A buffer layer may be provided on the substrate. The buffer layer has the function of blocking water and oxygen, and its main components include but are not limited to silicon nitrogen compound (SiN _x ), silicon oxygen compound (SiO _x ), silicon oxynitride (SiO _x N _y ) Wait. When the buffer layer is provided, the structural layers and electronic components of the OLED display panel, such as the anode electrode and the pixel definition layer, are located on the buffer layer.

Step S72, forming an anode electrode and a pixel defining layer on the substrate, the pixel defining layer surrounds and forms a plurality of grooves arranged in an array, the anode electrodes are located in the grooves one by one, and the plurality of The groove includes a plurality of first grooves, a plurality of second grooves, and a plurality of third grooves. The pixel definition layer includes a first retaining wall, a second retaining wall, and a third retaining wall. Between the first retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located on the third retaining wall. Between the wall and the first retaining wall.

In this embodiment, the anode electrode may be formed first, and then the pixel definition layer may be formed. For example, a photomask etching process (including film formation, exposure, development, and etching processes) may be used to form the anode electrode and the pixel definition layer respectively.

The process of forming the anode electrode by the photomask etching process, specifically:

First, a conductive layer and a photoresist layer covering the conductive layer are formed on the substrate. The conductive layer can be made of materials with good conductivity and high corrosion resistance, such as metal materials, including but not limited to molybdenum, nickel, palladium, cobalt, tungsten, rhodium, titanium, chromium, gold, silver, platinum, etc. Of course, in order to further improve its conductivity, the conductive layer can adopt a multi-layered metal structure, such as a three-layer metal structure of molybdenum, aluminum, and molybdenum, or a three-layer metal structure of nickel, copper, and nickel, and a three-layer metal structure of molybdenum, copper, and molybdenum. Layer metal structure, or three-layer metal structure of nickel, aluminum, and nickel. By providing a three-layer metal conductive structure, not only the conductivity of the conductive layer and the anode electrode prepared therefrom can be improved, but also the corrosion resistance of the conductive layer and the anode electrode can be improved.

Then, a photomask is used to expose the photoresist layer to obtain a photoresist layer with a predetermined pattern, wherein the photoresist layer with a predetermined pattern exposes the portion to be etched of the conductive layer. Specifically, the photomask is provided with a light-transmitting area. During the exposure process, the photomask is arranged above the photoresist layer at intervals. The pattern of the light-transmitting area is consistent with the final pattern to be etched, and the light passes through the light-transmitting area. Area and irradiate the photoresist layer for exposure. The exposed part of the photoresist layer is removed by the developer, while the unexposed part of the photoresist layer cannot be removed by the developer and is finally retained. Therefore, in a top view, The photoresist layer is transformed into a photoresist layer with a predetermined pattern, wherein the part of the photoresist layer removed by the developing solution exposes the part to be etched of the conductive layer.

Then, the part of the conductive layer that is not covered by the photoresist layer is removed by etching. In this embodiment, a dry etching process or a wet etching process may be used to remove the part of the conductive layer that is not covered by the photoresist layer. For the wet etching process, the part of the conductive layer covered by the photoresist layer is in full contact with the etching solution and undergoes a dissolution reaction to be completely removed, while the part that is not covered by the photoresist layer cannot be in contact with the etching solution. It is finally retained, and finally the conductive layer is etched into an anode electrode with a predetermined pattern.

Finally, the photoresist layer is removed by ashing to obtain the anode electrode.

The process and principle of using the photomask etching process to prepare the pixel definition layer can be referred to the above, and will not be repeated here. Of course, the pixel definition layer can also pass through a mask, and use physical vapor deposition (Physical Vapor Deposition). Vapor Deposition, PVD), pulsed laser deposition (Pulsed laser Manufactured by film forming processes such as PLD and magnetron sputtering.

In this embodiment, the pixel defining layer surrounds and forms a plurality of grooves arranged in an array, and each anode electrode is located in a groove. These grooves are used to define the pixel area of the OLED display panel. The pixel area includes a red pixel area. As an example, the three color pixel regions, the green pixel region and the blue pixel region, these grooves can be divided into a first groove for defining a red pixel area, a second groove for defining a green pixel area, and The third groove is used to define the blue pixel area.

The pixel definition layer can be divided into a first retaining wall, a second retaining wall, and a third retaining wall. The first groove is located between the first retaining wall and the second retaining wall, and the second groove is located between the second retaining wall and the second retaining wall. Between the three retaining walls, the third groove is located between the third retaining wall and the first retaining wall.

Step S73, by inkjet printing, drop the ink with the first organic light-emitting material into the first groove and form a film to form a first organic light-emitting layer, and drop the ink with the second organic light-emitting material into the first organic light-emitting layer. In the second groove and form a film to form a second organic light-emitting layer, and drop the ink in which the third organic light-emitting material is dissolved into the third groove and form a film to form a third organic light-emitting layer, wherein At least a spacer is formed between an organic light-emitting layer, the second organic light-emitting layer and the third organic light-emitting layer.

The first organic light emitting material is used to emit red light, the second organic light emitting material is used to emit green light, and the third organic light emitting material is used to emit blue light. In the embodiments of the present application, the ink in which the first organic light-emitting material is dissolved, the ink in which the second organic light-emitting material is dissolved, and the ink in which the third organic light-emitting material is dissolved can be simultaneously dropped into the first groove, the second groove, and the second groove, respectively. In the three grooves, the ink with the organic luminescent material can also be dropped into the three grooves in a predetermined order. For example, the ink with the first organic luminescent material can be dropped into the first groove first. , And then drop the ink with the second organic light-emitting material into the second groove, and finally drop the ink with the third organic light-emitting material into the third groove.

In the embodiment of the present application, the ink dropped into the three grooves is further dried, so that the ink with the first organic light-emitting material is formed into the first organic light-emitting layer, and the ink with the second organic light-emitting material is formed into the first organic light-emitting layer. Two organic light-emitting layers, and the ink with the third organic light-emitting material is formed into a film to form the third organic light-emitting layer. The first organic light emitting layer, the second organic light emitting layer, and the third organic light emitting layer form the organic light emitting layer of the OLED display panel. The thickness of the second organic light-emitting layer and the third organic light-emitting layer are equal and both are smaller than the thickness of the first organic light-emitting layer. It can be understood that the amount of the ink doped with the green organic light-emitting material and the amount of the ink doped with the blue organic light-emitting material is less than the amount of the ink doped with the red organic light-emitting material.

Because ink is dropped into the three grooves, the ink is dried to form an organic light-emitting layer. Before the film is formed, ink mixing will occur on the pixel defining layer at the junction of the pixel area. Therefore, the first organic light-emitting layer and the second organic light-emitting layer At least one spacer is formed between the two organic light-emitting layers and the third organic light-emitting layer, so that the ink mixing phenomenon is avoided under the blocking of the spacer.

In this embodiment, there are formed between the first organic light-emitting layer and the second organic light-emitting layer, between the first organic light-emitting layer and the third organic light-emitting layer, and between the second organic light-emitting layer and the third organic light-emitting layer. A second spacer is formed between the first organic light-emitting layer and the third organic light-emitting layer, and a second spacer is formed between the first organic light-emitting layer and the second organic light-emitting layer. A third spacer is formed between the three organic light-emitting layers, so that under the blocking of each spacer, the phenomenon of ink mixing in adjacent grooves when ink is dripped into each groove is avoided.

Step S74, forming a cathode layer in the spacer area.

After the spacer is formed, in order to prevent light leakage in the spacer, at the same time to increase the conductivity of the cathode of the panel, reduce the resistance of the cathode of the panel, and improve the uniformity of the panel light emission, a cathode layer is first arranged in the spacer, and the main cathode layer is The material is a metallic material, such as Ag, Al, Li, Mg, Ca and other metallic materials.

Step S75, forming an electron transport layer covering the first organic light-emitting layer, the second organic light-emitting layer, the third organic light-emitting layer, the pixel defining layer, and the spacer.

The electron transport layer can reduce the barrier of electron injection from the cathode electrode, so that electrons can be effectively injected from the cathode electrode into the OLED device. Lower the barrier for hole injection from the anode, so that holes can be effectively injected from the anode into the OLED device. Therefore, the main materials for preparing the electron transport layer can include LiF, MgP, MgF ₂ , and Al ₂ O ₃ .

Step S76, forming a cathode electrode covering the electron transport layer.

In the embodiment of the present application, an electron transport layer (ETL) and a cathode electrode (Cathode) can be formed sequentially through film forming processes such as PVD, PLD, and sputtering.

It should be understood that the foregoing steps have not produced all the structural components of the OLED display panel. For example, the OLED display panel further includes a hole injection layer (HIL) and a hole transport layer (Hole). transport Layer, HTL), electron injection layer (Electron Inject layer, EIL), the hole injection layer is formed on the anode electrode, the hole transport layer is formed between the hole injection layer and the organic light-emitting layer, and the electron injection layer is formed between the electron transport layer and the cathode electrode. The manufacturing process of these undescribed structural parts can refer to the prior art.

According to the aforementioned steps S71-S76, an OLED display panel can be obtained.

In the method for manufacturing the above-mentioned OLED display panel, the pixel defining layer is arranged as the first retaining wall, the second retaining wall, and the third retaining wall. The pixel defining layer surrounds the first grooves and the second grooves arranged in an array. The groove and the third groove, the first groove is located between the first retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located on the third retaining wall. Between the wall and the first retaining wall, drop the ink dissolved in the organic light-emitting material into the first groove, the second groove and the third groove to form an organic light-emitting layer, and the organic light-emitting layer is formed between the first organic light-emitting layer and the second organic light-emitting layer. A first spacer is formed between the layers, a second spacer is formed between the first organic light-emitting layer and the third organic light-emitting layer, and a third spacer is formed between the second organic light-emitting layer and the third organic light-emitting layer , By blocking the spacers, the mixing of inks with different organic light-emitting materials is avoided, which is beneficial to avoid the occurrence of pixel emission color shift and color mixing in the OLED display panel.

The above-mentioned embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can be made, and these all fall within the protection scope of this application. Therefore, the scope of protection of the patent of this application shall be subject to the appended claims.

Claims

An organic light emitting display panel, which includes:

Substrate

The anode electrode and the pixel defining layer are located on the substrate, the pixel defining layer surrounds and forms a plurality of grooves arranged in an array, the anode electrodes are located in the grooves one by one, and the plurality of grooves includes A number of first grooves, a number of second grooves, and a number of third grooves. The pixel definition layer includes a first retaining wall, a second retaining wall, and a third retaining wall. The first groove is located in the first retaining wall. Between the retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located between the third retaining wall and the third retaining wall. Between the first retaining wall;

The organic light-emitting layer is located on the anode electrode and includes a first organic light-emitting layer, a second organic light-emitting layer, and a third organic light-emitting layer. The first organic light-emitting layer is located in the first groove, and the second organic light-emitting layer is The layer is located in the second groove, and the third organic light-emitting layer is located in the third groove, wherein at least between the first organic light-emitting layer, the second organic light-emitting layer and the third organic light-emitting layer is at least Form a compartment;

An electron transport layer covering the first organic light-emitting layer, the second organic light-emitting layer, the third organic light-emitting layer, the pixel defining layer, and the spacer;

The cathode electrode covers the electron transport layer.
The organic light emitting display panel of claim 1, wherein the thickness of the second organic light emitting layer and the third organic light emitting layer are equal and both are smaller than the thickness of the first organic light emitting layer, and the first organic light emitting layer The spacer region is formed between the light emitting layer and the second organic light emitting layer and between the first organic light emitting layer and the third organic light emitting layer.
The organic light emitting display panel of claim 1, wherein a cathode layer is further provided in the spacer area, and the cathode layer is located on a surface of the electron transport layer away from the cathode electrode.
The organic light emitting display panel of claim 1, wherein the surface of the substrate is hydrophilic, and the surfaces of the first retaining wall, the second retaining wall, and the third retaining wall are all hydrophobic .
The organic light emitting display panel of claim 1, wherein the widths of the first groove, the second groove, and the third groove are all greater than the width of the spacer.
An organic light emitting display, wherein the organic light emitting display includes an integrated circuit and an organic light emitting display panel, the integrated circuit is connected to the organic light emitting display panel, and the organic light emitting display panel includes:

Substrate

The anode electrode and the pixel defining layer are located on the substrate, the pixel defining layer surrounds and forms a plurality of grooves arranged in an array, the anode electrodes are located in the grooves one by one, and the plurality of grooves includes A number of first grooves, a number of second grooves, and a number of third grooves. The pixel definition layer includes a first retaining wall, a second retaining wall, and a third retaining wall. The first groove is located in the first retaining wall. Between the retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located between the third retaining wall and the third retaining wall. Between the first retaining wall;

The organic light-emitting layer is located on the anode electrode and includes a first organic light-emitting layer, a second organic light-emitting layer, and a third organic light-emitting layer. The first organic light-emitting layer is located in the first groove, and the second organic light-emitting layer is The layer is located in the second groove, and the third organic light-emitting layer is located in the third groove, wherein at least between the first organic light-emitting layer, the second organic light-emitting layer and the third organic light-emitting layer is at least Form a compartment;

An electron transport layer covering the first organic light-emitting layer, the second organic light-emitting layer, the third organic light-emitting layer, the pixel defining layer, and the spacer;

The cathode electrode covers the electron transport layer.
7. The organic light emitting display of claim 6, wherein the thickness of the second organic light emitting layer and the third organic light emitting layer are equal and smaller than the thickness of the first organic light emitting layer, and the first organic light emitting layer The spacer region is formed between the layer and the second organic light-emitting layer and between the first organic light-emitting layer and the third organic light-emitting layer.
7. The organic light emitting display of claim 6, wherein a cathode layer is further provided in the spacer area, and the cathode layer is located on a surface of the electron transport layer away from the cathode electrode.
7. The organic light emitting display of claim 6, wherein the surface of the substrate has hydrophilicity, and the surfaces of the first retaining wall, the second retaining wall, and the third retaining wall all have hydrophobicity.
7. The organic light emitting display of claim 6, wherein the widths of the first groove, the second groove, and the third groove are all greater than the width of the spacer.
A method for manufacturing an organic light emitting display panel, which includes:

Provide a substrate;

An anode electrode and a pixel definition layer are formed on the substrate, the pixel definition layer surrounds and forms a plurality of grooves arranged in an array, the anode electrodes are located in the grooves one by one, and the plurality of grooves includes A number of first grooves, a number of second grooves, and a number of third grooves. The pixel definition layer includes a first retaining wall, a second retaining wall, and a third retaining wall. The first groove is located in the first retaining wall. Between the retaining wall and the second retaining wall, the second groove is located between the second retaining wall and the third retaining wall, and the third groove is located between the third retaining wall and the third retaining wall. Between the first retaining wall;

By inkjet printing, drop the ink with the first organic light-emitting material into the first groove and form a film to form the first organic light-emitting layer, and drop the ink with the second organic light-emitting material into the second recess. The second organic light-emitting layer is formed by forming a film in the groove, and the ink with the third organic light-emitting material is dropped into the third groove and formed into a film to form a third organic light-emitting layer, wherein the first organic light-emitting layer At least a spacer is formed between the layer, the second organic light-emitting layer and the third organic light-emitting layer;

Forming an electron transport layer covering the first organic light emitting layer, the second organic light emitting layer, the third organic light emitting layer, the pixel defining layer, and the spacer;

A cathode electrode covering the electron transport layer is formed.
11. The method for manufacturing an organic light-emitting display panel according to claim 11, wherein the thickness of the second organic light-emitting layer and the third organic light-emitting layer are equal and smaller than the thickness of the first organic light-emitting layer. The spacer region is formed between the first organic light emitting layer and the second organic light emitting layer and between the first organic light emitting layer and the third organic light emitting layer.
11. The method for manufacturing an organic light emitting display panel according to claim 11, wherein, before forming the electron transport layer, the method further comprises:

A cathode layer is formed in the spacer region.
The method for manufacturing an organic light emitting display panel according to claim 13, wherein the surface of the substrate is hydrophilic, and the surfaces of the first retaining wall, the second retaining wall, and the third retaining wall are all It is hydrophobic.
11. The method for manufacturing an organic light emitting display panel according to claim 11, wherein the widths of the first groove, the second groove and the third groove are all greater than the width of the spacer.